Versatile genius of the Renaissance, Leonardo created this drawing for his wall painting in Milan The Last Supper. The artist defined the role of artist as philosopher when he portrayed the moment Jesus said to the disciples ‘I tell you, one of you will betray me’. The earliest traces of red and black chalk, assumed to be by Leonardo’s hand, remain. This drawing, now more than 500 years old, was considered so important it was continually ‘updated’ and reworked.